Characterization of fractional cuts of co-solvent enhanced lignocellulosic fractionation lignin isolated by sequential precipitation. (January 2019)

• Record Type: Journal Article
• Authors: Meng, Xianzhi; Parikh, Aakash; Seemala, Bhogeswararao; Kumar, Rajeev; Pu, Yunqiao; Wyman, Charles E.; Cai, Charles M.; Ragauskas, Arthur J.
• Is Part Of: Bioresource technology. Volume 272(2019)
• Page Start: 202
• Page End: 208
• Publication Date: 2019-01
• Subjects: Lignin valorization -- Co-solvent enhanced lignocellulosic fractionation -- Sequential precipitation -- Molecular weight distribution; Biomass -- Periodicals; Biomass energy -- Periodicals; Bioremediation -- Periodicals; Agricultural wastes -- Periodicals; Factory and trade waste -- Periodicals; Organic wastes -- Periodicals; Bioénergie -- Périodiques; Déchets agricoles -- Périodiques; Déchets industriels -- Périodiques; Déchets organiques -- Périodiques; Déchets (Combustible) -- Périodiques; 662.88
• DOI: 10.1016/j.biortech.2018.09.130
• Languages: English
• ISSNs: 0960-8524

Abstract

Highlights: Three fractionation methods were combined to improve homogeneity of poplar lignin. Poplar lignin was fractionated by CELF pretreatment to obtain CELF lignin. CELF lignin was further fractionated into six distinct molar mass fractions. Low MW fractions were rich in phenolic and carboxylic acid OH groups. Parent CELF lignin and its fractions were all free of aryl ether linkages. Abstract: Lignin valorization is significantly hindered by the intrinsic heterogeneity of its complex structures and variability of biomass feedstocks. Fractionation of lignin can overcome these challenges by producing functionally distinct lignin cuts that can be further tailored to end products. Herein, lignin was extracted and depolymerized from poplar by the co-solvent enhanced lignocellulosic fractionation method with renewable THF to obtain CELF lignin. Several solvents were screened to separate soluble and insoluble fractions from the parent CELF lignin. The ethanol soluble portion was then fractionated into different molecular weight cuts via sequential precipitation of the lignin by reducing the concentration of THF. The physicochemical structures of different CELF lignin cuts were elucidated by GPC and NMR techniques. These results suggest that CELF lignin cuts with lower molecular weight contain progressively higher phenolic and carboxylic acid OH groups, which can be more suitable as green antioxidants than the parent lignin.